The invention relates to an ultrasonic imaging apparatus with an ultrasonic applicator for line-by-line ultrasonic scanning and with a device for displaying an echo perspective representation.
An ultrasonic imaging apparatus of this type is known e.g. from the publication "A New Real-Time Ultrasonic Diagnostic System for Dynamic and Still Images" by K. Ito et al from the Medical Electronics Journal, JEE, December '78, pages 60 to 64. The ultrasonic applicator of this apparatus is specifically an ultrasonic array which already scans an area of examination line-by-line by means of electronic continuous beam switching operation. According to FIG. 2 of the publication, this ultrasonic array can be shifted parallel to itself by a motor drive along the surface of the examination subject. With a pure B-mode there are thus obtained sectional images of the examination subject that are parallel to one another and in time sequence. When using suitable time gates, scanning in the C-mode or in the F-mode is also possible. In the C-mode, plane sections are obtained which run perpendicularly to the beam direction at a specific depth of the examination subject. With a corresponding programming of the time delay of the time member, the F-mode delivers surfaces of any shape.
The special type of displacement of the ultrasonic array over a large surface brings problems with regard to the correct coupling between the array and the body surface. Besides, the application is limited to soft tissue, e.g. the stomach region. Subcostal layer images cannot be obtained because of the shadow effects of the ribs.